// https://syzkaller.appspot.com/bug?id=27d313ef3e5b11d1d75cb07a6e79d8fe76904e89 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_bpf #define __NR_bpf 321 #endif static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static int runcmdline(char* cmdline) { int ret = system(cmdline); if (ret) { } return ret; } #define MAX_FDS 30 static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } static void setup_binderfs() { if (mkdir("/dev/binderfs", 0777)) { } if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) { } if (symlink("/dev/binderfs", "./binderfs")) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } static int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535"); setup_binderfs(); loop(); exit(1); } static int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static void close_fds() { for (int fd = 3; fd < MAX_FDS; fd++) close(fd); } static void setup_fault() { static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) exit(1); } } } static void setup_binfmt_misc() { if (mount(0, "/proc/sys/fs/binfmt_misc", "binfmt_misc", 0, 0)) { } write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:\x01::./file0:"); write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:\x02::./file0:POC"); } static void setup_usb() { if (chmod("/dev/raw-gadget", 0666)) exit(1); } static void setup_sysctl() { char mypid[32]; snprintf(mypid, sizeof(mypid), "%d", getpid()); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", mypid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } #define SWAP_FILE "./swap-file" #define SWAP_FILE_SIZE (128 * 1000 * 1000) static void setup_swap() { swapoff(SWAP_FILE); unlink(SWAP_FILE); int fd = open(SWAP_FILE, O_CREAT | O_WRONLY | O_CLOEXEC, 0600); if (fd == -1) { exit(1); return; } fallocate(fd, FALLOC_FL_ZERO_RANGE, 0, SWAP_FILE_SIZE); close(fd); char cmdline[64]; sprintf(cmdline, "mkswap %s", SWAP_FILE); if (runcmdline(cmdline)) { exit(1); return; } if (swapon(SWAP_FILE, SWAP_FLAG_PREFER) == 1) { exit(1); return; } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void loop(void) { intptr_t res = 0; res = syscall(__NR_socket, /*domain=*/1ul, /*type=*/2ul, /*proto=*/0); if (res != -1) r[0] = res; *(uint32_t*)0x2000e000 = 0xe; *(uint32_t*)0x2000e004 = 4; *(uint64_t*)0x2000e008 = 0x20000540; memcpy( (void*)0x20000540, "\xb4\x05\x00\x00\xfd\xff\x7f\x00\x61\x10\x58\x00\x00\x00\x00\x00\xc6\x00" "\x00\x00\x00\x00\x00\x00\x95\x00\x00\x00\x00\x00\x00\x00\x9f\x33\xef\x60" "\x91\x6e\x6e\x71\x3f\x1e\xeb\x0b\x72\x5a\xd9\x9b\x81\x7f\xd9\x8c\xd8\x24" "\x49\x89\x49\x71\x4f\xfa\xac\x8a\x6f\x77\x06\x00\xdc\xb9\x55\xf2\x1f\x3c" "\xa9\xe8\x22\xd1\x82\x05\x4d\x54\xd5\x3c\xd2\xb6\xdb\x71\x4e\x4b\xeb\x54" "\x47\x00\x00\x01\x00\x00\x00\x00\x8f\x2b\x90\x00\xf2\x24\x25\xe4\x09\x7e" "\xd6\x2c\xbc\x89\x10\x61\x01\x7c\xfa\x6f\xa2\x6f\xa7\x08\x8c\x60\x89\x7d" "\x4a\x61\x48\xa1\xc1\x14\xd8\xda\x01\x1b\xde\x60\xbe\xac\x67\x1e\x8e\x8f" "\xde\xcb\x03\x58\x8a\xa6\x23\xfa\x71\xf3\x1b\xf0\xf8\x71\xab\x5c\x2f\xf8" "\x8a\xfc\x60\x02\x7f\x4e\x5b\x52\x71\x0a\xee\xe8\x35\xcf\x0d\x00\x00\x00" "\x00\x98\xb5\x1f\xe6\xb1\xb8\xd9\xdb\xe8\x7d\xcf\xf4\x14\xed\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\xb3\x47\xab\xfb\x35\x2a\x08\x0f\x81\x40\xe5\xfd" "\x10\x74\x7b\x6e\xcd\xb3\x54\x05\x46\xbf\x63\x6e\x3d\x6e\x70\x0e\x5b\xc6" "\xd3\xfd\x54\xf4\x74\x3b\x22\xeb\x9e\x14\x03\xe6\xc8\xf7\xa1\x87\xea\xf6" "\x0f\x3a\x17\xf0\xf0\x46\xa3\x07\xa4\x03\xc1\x9d\x98\x29\xc9\x0b\xd2\x11" "\x42\x52\x58\x15\x67\xac\xae\x71\x5c\xbe\x32\x67\x33\x51\x6f\x32\xc5\xb9" "\x10\x40\x06\x23\xd2\x41\x95\x40\x5f\x2e\x76\xcc\xb7\xb3\x7b\x41\x21\x5c" "\x18\x4e\x73\x1f\xb1", 329); *(uint64_t*)0x2000e010 = 0x20003ff6; memcpy((void*)0x20003ff6, "GPL\000", 4); *(uint32_t*)0x2000e018 = 4; *(uint32_t*)0x2000e01c = 0xfd90; *(uint64_t*)0x2000e020 = 0x2000cf3d; *(uint32_t*)0x2000e028 = 0; *(uint32_t*)0x2000e02c = 0; memset((void*)0x2000e030, 0, 16); *(uint32_t*)0x2000e040 = 0; *(uint32_t*)0x2000e044 = 0; *(uint32_t*)0x2000e048 = -1; *(uint32_t*)0x2000e04c = 8; *(uint64_t*)0x2000e050 = 0x20000000; *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x2000e058 = 0x366; *(uint32_t*)0x2000e05c = 0x10; *(uint64_t*)0x2000e060 = 0x20000000; *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x20000008 = 0; *(uint32_t*)0x2000000c = 0; *(uint32_t*)0x2000e068 = 0x1dd; *(uint32_t*)0x2000e06c = 0; *(uint32_t*)0x2000e070 = -1; *(uint32_t*)0x2000e074 = 0; *(uint64_t*)0x2000e078 = 0; *(uint64_t*)0x2000e080 = 0; *(uint32_t*)0x2000e088 = 0x10; *(uint32_t*)0x2000e08c = 0; res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x2000e000ul, /*size=*/0x48ul); if (res != -1) r[1] = res; *(uint32_t*)0x20000200 = 0xf; *(uint32_t*)0x20000204 = 4; *(uint32_t*)0x20000208 = 4; *(uint32_t*)0x2000020c = 0x12; *(uint32_t*)0x20000210 = 0; *(uint32_t*)0x20000214 = -1; *(uint32_t*)0x20000218 = 0; memset((void*)0x2000021c, 0, 16); *(uint32_t*)0x2000022c = 0; *(uint32_t*)0x20000230 = -1; *(uint32_t*)0x20000234 = 0; *(uint32_t*)0x20000238 = 0; *(uint32_t*)0x2000023c = 0; *(uint64_t*)0x20000240 = 0; res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000200ul, /*size=*/0x48ul); if (res != -1) r[2] = res; *(uint32_t*)0x20000080 = r[2]; *(uint32_t*)0x20000084 = r[1]; *(uint32_t*)0x20000088 = 0x26; *(uint32_t*)0x2000008c = 0; *(uint32_t*)0x20000090 = 0; *(uint32_t*)0x20000094 = -1; *(uint64_t*)0x20000098 = 0; syscall(__NR_bpf, /*cmd=*/8ul, /*arg=*/0x20000080ul, /*size=*/0x10ul); *(uint32_t*)0x20000140 = r[2]; *(uint64_t*)0x20000148 = 0x20000180; *(uint64_t*)0x20000150 = 0x200000c0; *(uint32_t*)0x200000c0 = r[0]; *(uint64_t*)0x20000158 = 0; syscall(__NR_bpf, /*cmd=*/2ul, /*arg=*/0x20000140ul, /*size=*/0x20ul); *(uint16_t*)0x200001c0 = 1; memcpy((void*)0x200001c2, "./" "file0\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000", 108); syscall(__NR_bind, /*fd=*/r[0], /*addr=*/0x200001c0ul, /*addrlen=*/0x6eul); *(uint64_t*)0x200063c0 = 0x20002ac0; *(uint16_t*)0x20002ac0 = 1; memcpy((void*)0x20002ac2, "./" "file0\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000", 108); *(uint32_t*)0x200063c8 = 0x6e; *(uint64_t*)0x200063d0 = 0; *(uint64_t*)0x200063d8 = 0; *(uint64_t*)0x200063e0 = 0; *(uint64_t*)0x200063e8 = 0; *(uint32_t*)0x200063f0 = 0; *(uint32_t*)0x200063f8 = 0; inject_fault(7); syscall(__NR_sendmmsg, /*fd=*/r[0], /*mmsg=*/0x200063c0ul, /*vlen=*/1ul, /*f=*/0ul); close_fds(); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); setup_sysctl(); setup_binfmt_misc(); setup_fault(); setup_usb(); setup_swap(); do_sandbox_none(); return 0; }